Liquid fuel composition



LIQUID FUEL COMPOSITION Joseph Francis Wood and Charles Howard Hopkins, Pawhuska, kla., assignors to Skelly Oil Company, Tulsa, 01:18., a corporation of Delaware No Drawing. Application March 16, 1955 Serial No. 494,807

6 Claims. (CI. 44-58) This invention relates to organic liquid compositions and more particularly to liquid hydrocarbons into which an'additive has beenincorporated.

It is known that'certain liquid hydrocarbons, such as gasoline, kerosene, diesel oils, furnace oils and lubricating oils, have a tendency to form gumsand gum compositions during storage under ordinary conditions. This tendency is not desirable in motorfucls, such as gasoline, diesel fuels or furnacejoils, since the gums or gumlike substances may result in valveand line clogging in carburetors and other fuel-feedingor fuel induction systems or the formation of deposits in the combustion zone. Also upon storage of prod'uctsof this general character the by drocarbon compositions have a tendency to accumulate small amounts of water due, at least in part, to condensation from the atmosphere. Such water interferes with the use of the composition as a fuel or lubricant and may also give ris'e'to corrosion problems. In the past, various additives .have been proposed to combat the gum problem but-these compoundsare generally of the nature of detergents which, in. so far ..as;they may be effective, act to prevent the aceumulation oflg-umin various types of equipmentin which the hydrocarbon liquid is employed, the detergents many preventing the accumulation of gum or gumlike materials. In so far as the water problem is concerned, the additives that have been employed for this purpose are generally corrosion inhibitors and freezing point depressants. However, they are generally not effective for removing the water from the hydrocare bon liquid.

Accordingly, an'object of this invention is the provision of.a-..liquid hydrocarboncomposition having contained therein an additive which prevents the formation of gums,

lacquers, varnishes and similar materials in the fuel induction systems and combustion zones in which the hydrocarbon may be used.

Alfurther object of the inventionis the provision of an additive for a hydrocarbon which prevents the accumula- I tion of-water therein even upon storage thereby providing a gasoline, kerosene, diesel fuel, furnace oil, lubricating oil or other heavy liquid petroleum product which is essentially anhydrous afall times;

A further object of this invention is the provision of L amotor fuel which modifies or eliminates combustion chamber deposits when employed so that such deposits do not change the operatingconditions of the engine.

U A still further object of this invention isthe provision of an additive for'a motor fuelwhic'h improves the volatility thereof without giving rise to detrimental vapor lock effects, thereby improving the starting characteristics of the fuel.

A' further objeect of this invention is the provision of an additive for gasoline or other motor fuel which has a research octane blending value'in excess of 100.

A further objectof this invention is the provision of an 7 additive for 'a' gasoline which raises the practicallimit of F- P S t it see sim 1 v l Paiented Mar. 17,1959

I A still further object of this invention is the provision problems incident to freezingin storage and induction systems. i

A further object of this invention is the provision of a motor fuel in which the exhaust gas odors have been diminished.

.A further object of this invention is the provision of a hydrocarbon composition of increased stability against oxidation. i I

. A still further object of this invention is the provision of a hydrocarbon product providing increased spark plug lifejand valve life through the removal or minimizing of gumlike deposits. I

A'still further object of thisin cation is the provision of a furnace oil which is stabilized against gum formation and the accumulation of water therein.

Further and additional objects will appear from the following description and the accompanying claims,

,,In accordance with thisinvention, a liquid hydrocarbon or other organic liquid is treated with a ketal in order to provide a composition having one or more of the above indicated desirable characteristics. The ketal employed in accordance with this invention is 2,2-dimethoxypropane, :lheket'al reacts with water to produce one molecule of an acetone and two molecules of a methanol with the consequent consumption of one molecule of water. The ketal,

aswell as the ketone and alcohol, serves as a solvent which tends to prevent the formation ofgum, lacquers, varnishes or the like during storage of thehydrocarbon or when the hydrocarbon may be burned in an internal combus: tion engine. The ketal employed as an additive in accordance with the disclosure of this invention is to be sharply distinguished from those compounds which are specifically known as acetals andwhich are the condensation products of two mols of an alcohol with one mol of an aldehyde. Thus if acetals are employed asadditives fora hydrocarbon, they will react with accumulated water to form an alcohol and an aldehyde; Such aldehydes are wholly undesirable in hydrocarbon liquids since the aldehydes themselves tend to undergo polymerization thereby producing gummylike materials and resinous products which are avoided in the products of this invention. I

In accordance with one embodiment of this invention, it is preferred to add to the hydrocarbon liquid, in addi tion to the ketal, a substance which will catalyze the reaction between water and the ketal, .thereby insuring prompt removal of anyaccumulatedwater as such from the hydrocarbon liquid. 'Such catalysts are generally acidic in nature and are preferably those organic compounds which are soluble in the liquid hydrocarbon and which may be readily hydrolyzed. to form an"-acid.'

- Specific compounds of this natureare the hydrochlorides of the following organic nitrogenous bases: e Aminophenol' Phenylhydrazine Aniline Pic'oline Anisidine Piperidine I so-quinoline- Pyridine Lutidine Pyrolidine N-methyl aniline Quinoline N-methyl toluidine Toluidine N-methyl xylidine Xylidine Phenetidine I 0 However, it vwillbe apparentthat-other acid-salts ofthe above-mentioned or other; organic nitrogenous bases may be some. tort i u ne i rs Elms-the i above give an acidreaction to the. water which has no cumulated but when the. water'has all reacted, the salts reform and are not essentially acidic in nature.

The amount of ketal. to be added to the hydrocarbon liquid will depend in a large measure upon the character the expected storage conditions. Generally speakingthe amount of ketal employedflis between about 0.005 and 4.0 volume percent of the hydrocarbon. Preferably,

a period of operation the best commercial gasolines no longer satisfied the octane requirements of the engine by the manufacturers recommended basic spark setting. This particular car model is representative of a large number of cars now being manufactured. The first step was to drive the car until theengine deposits had stabilized and the octane requirement leveled off. A standard commercial leaded). gasoline having a. research method octane rating of 92.4 was used during the preliminary stabilization period; After-about6,000 miles, frequent octane requirement'tests', were madeto determinethe car octane demand. At this point the octane requirement was constant at areference fuel octane number of 95.5. of the liquid; the purpose for which it is to be used, and

however, the amounts will range between 0.01and2.0 percent by volume. Such amounts have been found to be wholly eifcctive fonthe'treatment of gasoline, furnace oil and lubricating oil compositions. However, it is con ceivable that in certain special instances, such as in the formulation of jet engine fuels, percentages of ketal higher than indicated above could be employed to advantvveen about 0.001 and LQ'percent by weight of the ketal present in the final composition.

' For a more complete understanding of this invention, reference will now be modeto certain examples and 'test results which have been=carried out demonstratingthe advantages that -maybe obtainedby adding a ketal'to a-hydrocarbon liquid as-previously suggested.

Example 1 A'gasoline composition was prepared admixing 1.8 cc. of 2,2-dimethoxypropaneto eachgallou of a conventional leaded gasoline, the concentrationof ketal in the final product being 0.0475 volume percent. The ketal was thoroughly dispersed in the gasoline since it is completely At 7,912 miles the can-engine was disassembled for inspection. Considerable gum was found to be present in the carburetor and the amount of combustion chamber deposit on the pistons, valves, block and head was observed, but the deposits were not disturbed. The engine was then reassembled.

After reassembly of the engine, the use of a gasoline containing 1.8 cc. ofv 2,2-dimethoxypropane per gallon was begun. The gasoline was the same as used initially except for the addition of the ketal. After 1,000'miles of town driving using the gasoline containing ketal, the octane requirement ofthe engine had decreased to a reference fuel octane number of 92.0. Another 2,000 miles of similar driving indicated that the octane requirement had leveled otf'at 92.0. This'test, therefore, indi cated that the use ofthe ketal lowered the octane require miscible'therein in --the proportions employed. Theresulting fuel was employedina spark-ignited, water-cooled internal combustion enginewhich had 'previously been intentionally fouled with-gum, varnish, lacquer and carbonaceous deposits in-thelfuel system and in the combustion chamber to a point wherein starting of the engine wasexceedingly difiicult and'uniform operation was impossible to maintain After 4 hours operation of the engine on the ketal-.hydrocarbonfue1 blend,'the engine started with ease, operated at constant speed without continual adjustments, and the operation of the engine was generallysmooth. At the end of 40 hours" operation Outhe; ketal-hydrocarbon -fu'el-blend,the engine was ex amined revealing theremoval of all gum, varnish and lacquer from the fuel' storage and induction system, a total absence of ac umulated water in the fuel ,tank and fuel strainer, and a substantial reduction in the amount of carbonaceous material in the combustion chamberon the intake and exhaustvalves and on the spark plug electrode. Deposits remaining in the combustion chamher were examined and compared to original deposit samples and were .found' to be more porous, not as hard, and less adherent 'to the exposed metalwitha tendency to flake off. Example 2 ment of this car from'95i5 to 92.0, or about 3.5 reference fuel octane numbers.

' In this same test and before the k'etal was added to the fuel, the car road-rated the commercial fuelfrom 1.5 to 2.5 o'ctanenumbersbelow-the ASTMeCFR re search octane number-for that fuel; After the ketal was added to the commercial fuel, the road,- rating for this fuel was from 0:5 octane numbcr'less to 1.0 octane num-. 'er'higher than the research octane rating, thereby demonstrating an improvementin-the road octane rating of the commercial fuel-when-the-ketal was added. Other improvements in performance characteristics of the engine were noted.

- Example 3 The engine performance improvement andelimination of carbon deposits noted in. the foregoing examples are due to the presence of-the ketalin the fuel when burned. In a situation where the fuel is to be subjected to storage with a tendency toaccumulate water'by' condensation from the atmosphereor otherwise,'-it is desirable to use the readily hydrolyzable catalyst. toinsure that the hydrolytic reaction. will occur: readily. Thusya fuel which will remain anhydrous :during normal storage conditions including storage in an automobilegasoline-tank is one in which about 2.cc. of 2,2-dimethoxypropane-have been added to each gallonv ofggasoline and into which has been incorporated about 0.05 percent (based'upon the weight of the ketal) of aniline hydrochloride or pyridine hydrochloride. In such a-fuelwater accumula-- tion is prevented and the acetone andmethyl'alcoholformed by hydrolysis-also. contribute: to thedesirable performance characteristics of the motor fuel noted above. r

Example 4 A No. Z'furnace oil was treated with.4.0 cc. per gallon. (0.11 volume percent) of 2,2 -dimethoxypropane.and 0.1 percent (based on the weight of the. ketal) of pyridine hydrochloride and subjeeted'to storage. The furnace oil A.modern-1954-'model automobilewas chosen-having a high compression engine. which-had a characteristic such zthatt. after enginodepositsi had accumulated during tendency to, clog the lines, valvesandlnoz zles of; the, fuel,

induction system; In the foregoing specifioexamples have been given relative to gasolines and furnace oils that may contain additives in accordance with this invention. It will, however, be apparent that other specific procedures, variations and formulations may be employed without departing from the spirit and scope of this invention. For example, in one instance it has been possible to eliminate acceleration knock, erratic cold starting and performance of an engine by the addition of 500 cc. of dimethoxypropane to 15 gallons of gasoline contained in the gasoline tank. The improvement was audibly noticeable almost instantly (less than miles operation) and the improved engine operation was evident at the first cold start.

While the invention has been specifically described with respect to the treatment of gasoline and furnace oils, it will also be apparent that it has broader applicability in connection with jet fuels, kerosenes, lubricating oils and other organic liquid treatment wherein water accumulation or gum formation may present a problem. For example, it has been found that the ketal is of use in connection with the treatment of detergent and nondetergent lube oils from which it is possible to eliminate the water or to prevent the accumulation thereof. The accumulation of water is a serious problem in automotive engine lubrication particularly where hydraulic valve lifters are employed. By eliminating the water, corrosive damage to the valve lifters and other engine parts is minimized if not eliminated in most cases.

Another field of application of this invention resides in the elimination of the effects of water corrosion in crude oil primary processing. Thus in instances where the presence of water is undesirable a ketal as above defined and a readily hydrolyzable salt may be added to the oil in order to remove water or to prevent its accumulation prior to processing.

An important feature of this invention is that the ketal additive is not incompatible with other additives that may be employed in the hydrocarbon liquid. Thus the gasolines or other oils may contain other additives such as lead tctraethyl, organic phosphates, detergents, alcohols or glycols without adversely affecting the intended use of the composition.

While several particular embodiments of this invention are shown above, it will be understood, of course, that the invention is not to be limited thereto, since many modifications may be made, and it is contemplated, therefore, by the appended claims, to cover any such modifications as fall within the true spirit and scope of this invention.

We claim:

1. A liquid hydrocarbon fuel having dispersed therein between about 0.01 and about 2.0 volume percent of 2,2- dimethoxypropane.

2. A liquid hydrocarbon fuel having added thereto between about 0.005 and about 4 percent by volume of 2,2-dimethoxypropane.

3. A gasoline motor fuel having dispersed therein between about 0.005 and about 4.0 volume percent of 2,2- dimethoxypropane.

4. A gasoline motor fuel having dispersed therein between about 0.01 and 2.0 volume percent of 2,2-dimethoxypropane.

5. A leaded gasoline containing about 0.0475 volume percent of 2,2-dirnethoxypropane.

6. The product of claim 2 wherein said fuel is a furnace oil.

References Cited in the file of this patent UNlTED STATES PATENTS 1,570,059 Hammond Jan. 19, 1926 1,582,420 Nikaido Apr. 27,1926 2,106,662 Savage Jan. 25, 1938 2,143,870 Ellis Jan. 17, 1939 2,312,790 Backoff et a1. Mar. 2, 1943 2,473,994 Gresham June 21, 1949 2,626,209 Morrell Jan. 20, 1953 FOREIGN PATENTS 668,664 Great Britain Mar. 19, 1952 

1. A LIQUID HYDROCARBON FUEL HAVING DISPERSED THEREIN BETWEEN ABOUT 0.01 AND ABOUT 2.0 VOLUME PERCENT OF 2.2DIMETHOXYPROPANE. 